/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: user
 * Date: 2024-03-28
 * Time: 15:10
 */
public class MySingleLinkedLIst {
    static class ListNode{
        public int val;
        public ListNode next;

        public ListNode(int val) {
            this.val = val;
        }
    }
    ListNode head ;
    //头插法
    public void addFirst(int val){
        ListNode node = new ListNode(val);
            node.next = head;
            head = node;
    }
    //尾插法
    public void addLast(int val){
        ListNode node = new ListNode(val);
        if(head == null){
            addFirst(val);
        }
        else{
            ListNode cur = head;
            while (cur.next != null){
                cur = cur.next;
            }
            cur.next = node;
        }
    }
    //任意位置插入,第一个数据节点为0号下标
    public void addIndex(int index,int val){
        try{
            checkAddIndex(index);
        }
        catch (AddIndexException e){
            e.printStackTrace();
        }
        if(index == 0){
            addFirst(val);
            return;
        }
        if(index == size()){
            addLast(val);
            return;
        }
        ListNode node = new ListNode(val);
        ListNode cur = head;
        int count = 0;
        while (count != index - 1){
            cur = cur.next;
            count++;
        }
        node.next = cur.next;
        cur.next = node;
    }
    private void checkAddIndex(int index)throws AddIndexException{
        if(index < 0||index > size()){
         throw new AddIndexException("index非法！！！");
        }
    }
    //查找是否包含关键字key是否在单链表当中
    public boolean contains(int key){
        ListNode cur = head;
        while (cur != null) {
            if(cur.val == key){
                return true;
            }
            cur = cur.next;
        }

        return false;
    }
    //删除第一次出现关键字为key的节点
    public void remove(int key){
        if(head == null)
        {
            return;
        }
        if (head.val == key){
            head = head.next;
            return;
        }
        ListNode cur = head;
        while (cur.next != null) {
            if(cur.next.val == key){
              cur.next = cur.next.next;
              return;
            }
            cur = cur.next;
        }
    }
    //删除所有值为key的节点
    public void removeAllKey(int key){
        if(head == null)
        {
            return;
        }
        ListNode cur = head;
        ListNode curN= head;
        while (curN != null) {
            if(curN.val == key){
                cur.next = curN.next;
                curN = curN.next;
            }
            else {
                cur = curN;
                curN = curN.next;
            }
        }
        if (head.val == key){
            head = head.next;
        }

    }
    //得到单链表的长度
    public int size(){
        ListNode cur = head;
        int count = 0;
        while (cur != null) {
            cur = cur.next;
            count++;
        }
        return count;
    }
    //清空链表
    public void clear() {
        ListNode cur = head;
        while (cur != null){
            ListNode curN = cur.next;
            cur.next = null;
            cur = curN;
        }
        head = null;
    }
    // 打印链表
    public void display() {
        ListNode cur = head;
        while(cur != null){
            System.out.print(cur.val + " ");
            cur = cur.next;
        }
    }

}
